Hammer pulverizer



May 16, 1933.

J. AUBE. 1,908,724

HAMMER PULVERIZER Filed March 14, 1952 IEEE Patented May 16, 1933 UNITED STATES PATENTY @FFCE JEAN' AUBE, OF PARIS, FRANCE HAIVIMER PULVERIZER Application led March 14, 1932, Serial No. 598,861, and in =France November 3, 1931.

The present invention has for object improvements in hammer pulverizers, more particularly to the method of securing the blades or vanes of the crusher on the disc of the. rotor which is adapted to allow of giving to this disc a very reduced thickness; whilst providing a strong assembly, the elements of which can be easily designed in function of the stresses to which they are subjected, so that it is possible to give them the shape and dimensions ensuring the best conditions of operation.

Finally, the side cheek members of the disc of the rotor are so shaped as to ensure an eflicient and durable protection and as to be easily and economically replaced.

The accompanying' drawing illustrates, by way of example only, a preferred form of carrying out the subject-matter of the invention:

Fig. l is a section made according to line I-I of Fig. 2.

Fig. 2 is a section made according to line II-II of Fig. l.

The crushing hammers 7 are secured on the disc 6 of the rotor by means of double fork members, each having two arms 74 embracing the edge of the disc, and two other arms 74a set perpendicular to the arms 74, and between which the hammer 7 is mounted.

Eachdouble fork member is secured on the disc 6 by means of a stud 75 made of high resistance steel, forcibly fitted in housings provided in these two members, and designed 35 for alone resisting to the centrifugal stresses which are exerted on the hammer and on the fork piece.

A rivet 76, terminating in two frustumshaped parts 7 6a supported by bearing portions of corresponding shape of the arms 74, hold the latter in their normally spaced position.

The hammer 7 is secured to the fork piece by means of a bolt 77 passing through this hammer and the arms 74a, and on the ends of which are screwed two nuts 7 S, 7 8a. y

The hammer lits between both arms 74a with some play, and it is longitudinally held stationary by a shoulder of the bolt 77. This shoulder can be either perpendicular to the aXis of the bolt,or, preferably, it can beof i i Vconical shape, as shown at 77a; it bears upon the hammer through thel medium of a ring 79, the central hole of which has a profile corresponding to that of the shoulder. y

The conical shape given to the shoulder177a has the advantage that it does not cause a sudden variation of section Aof the bolt and, consequently, does not diminish its resistance.

Moreover, it thus has a sufficient surface for suitably bearing on the ring 79 and firmlyholding the hammer in position.

The screw-threaded portions receiving Y both nuts 78, 7 8a have pitches of the same 65 direction, but of dierent values, and these nuts being held stationary by braking members 80, 80a, any rotation of the bolt 77 and, consequently, any untimely loosening of the assembly are prevented.

The fork piece 7 4-7 4a has a constant cross section throughout its length, and it does not have, at the hammerany enlarged portion as ordinary securing fork pieces; it results therefrom that it operates solely by tension, 75 that is to say in better conditions than these ordinary fork pieces which are subjected, by centrifugal force, in their enlarged portion, to bending stresses.

Moreover, the particular method of secur- 80 ing the fork pieces on the disc 6 allows of giving to the latter a very reduced thickness. i

l The hammers 7 are also heldin position by two thin plates 8l, arranged on either side of the disc 6, and provided, at their periphery, with cut-away parts in which these hammers t.

The plates 81 are themselves covered and held in position by protecting cheek members 82, of suitable thickness, and the diameter of which is such that they are tangent to the inner edges of the hammers 7.

The wear of the cutaway plates 81 is thus reduced to the minimum and is supported nearly entirely by the cheek members 82; 95 the latter, having the shape of simple discs perforated at their centre with a hole through which passes the shaft of the rotor, are very simple to manufacture and can be replaced at small cost. v

The plates 81 provided with indentations, are protected by the cheek members 82 having smooth edges, so that the wear is supported nearly entirely by these cheek members. The abrasive dust of the crushing chamber thus cannot form in the cheek members grooves directed according to a cercle tangent tothe inner edges of the hammers.

The plates or discs 81, the manufacture of which is more costly than that of the cheek members, can thus last a very long time without having to replace them.

I claim:

l. In a hammer pulverizer, the combination ot a .crushing chamber, a rotor disc adapted to rotate in this crushing chamber, crushing hammers on this disc, a double forkpiece for each crushing hammer, this forkpiece having, at one end, two arms arranged for embracing the edge of the said rotor disc and, at the other end, two arms arranged for embracing the said hammer, the ,arms of one end being set perpendicular relatively Vto the arms of the other end.

2. In a hammer pulverizer, the combination of a crushing chamber, a rotor disc, arranged for rotating in this crushing chamber, crushing hammers on this disc, a double forkpiece for each crushing hammer, this forkpiece having, at one end, two arms arranged for embracing the edge of the said rotor disc, and, at thefother end, two arms arranged for embracing the said hammer, the arms of one end being set perpendicular relatively to the arms of the other end, a bolt arranged for passing through the said crushing hammer and the two corresponding arms of the said forli-piece, nuts on both ends of the said bolt, the screw-threads of the nuts having different pitches. Y

3. In a hammer pulverizer, the combination of a crushing chamber, a rotor disc arranged for rotating in this crushing chamber, crushing hammers on this disc, a plate on either side of the said disc, this plate having, in its periphery, notches in which the said crushing hammers fit, a circular protecting cheek-member 0n each of the said plates, the peripheral edge of this cheek-member being so arranged as to be tangent to the inner edges of the said hammers.

In testimony whereof I have hereunto affixed my signature.

JEAN AUBE. 

